title: Theoretical studies on the molecular structure and vibrational spectra of some dimethyl substituted pyridine derivatives.
abstract: The molecular geometries, normal mode frequencies, intensities and corresponding infrared assignments of monomeric and dimeric 2,3-dimethylpyridine, 2,4-dimethylpyridine, 3,4-dimethylpyridine, 3,5-dimethylpyridine and monomeric 2,6-dimethylpyridine in the ground state were investigated at the density functional theory (DFT)-B3LYP level using the 6-311+G(d, p) basis set. The vibrational frequencies and geometric parameters of C-H stretching and bending in the fundamental region were calculated and compared to the Fourier transform infrared (FT-IR) data obtained. In the studied monomeric and dimeric dimethyl substituted pyridine derivatives, the C-H stretching and bending frequency shifts that occur between the dimer and the monomer may be diagnostic of the magnitude of dimerization energy. As supported by data in the literature, the most stable dimeric form was obtained for the 3,4-dimethylpyridine molecule.
authors.affiliation: Department of Physics, Faculty of Arts and Science, Eskisehir Osmangazi University, 26480 Eskişehir, Turkey. gkurkcuo@ogu.edu.tr
authors.forename: Güneş Süheyla
authors.initials: GS
authors.lastname: Kürkçüoğlu
authors.forename: Ilkan
authors.initials: I
authors.lastname: Kavlak
authors.forename: Taner
authors.initials: T
authors.lastname: Arslan
authors.forename: Cemil
authors.initials: C
authors.lastname: Oğretir
mesh_terms: D000818:Animals; D019281:Dimerization; D008958:Models, Molecular; D011725:Pyridines / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013816:Thermodynamics
chemical_list: D011725:Pyridines